iOS7 UI兼容 导航栏按钮边框 UINavigationItem left and right padding

ios7中得导航栏按钮相对于ios7之前的版本会出现12个像素左右的偏移，这使得很多UI不是那么协调了。为了解决一个问题，

重写UINavigationItem的setLeftBarButtonItem和setRightBarButtonItem方法，使之与之前版本兼容；

代码如下：

@interface UINavigationItem (margin)

@end

@implementation UINavigationItem (margin)

if __IPHONE_OS_VERSION_MAX_ALLOWED > __IPHONE_6_1

• (void)setLeftBarButtonItem:(UIBarButtonItem *)_leftBarButtonItem
  {
  if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0)
  {
  UIBarButtonItem *negativeSeperator = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
  negativeSeperator.width = -12;

  if (_leftBarButtonItem)
  {
      [self setLeftBarButtonItems:@[negativeSeperator, _leftBarButtonItem]];
  }
  else
  {
      [self setLeftBarButtonItems:@[negativeSeperator]];
  }
  [negativeSeperator release];
  

  }
  else
  {
  [self setLeftBarButtonItem:_leftBarButtonItem animated:NO];
  }
  }

• (void)setRightBarButtonItem:(UIBarButtonItem *)_rightBarButtonItem
  {
  if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0)
  {
  UIBarButtonItem *negativeSeperator = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
  negativeSeperator.width = -12;

  if (_rightBarButtonItem)
  {
      [self setRightBarButtonItems:@[negativeSeperator, _rightBarButtonItem]];
  }
  else
  {
      [self setRightBarButtonItems:@[negativeSeperator]];
  }
  [negativeSeperator release];
  

  }
  else
  {
  [self setRightBarButtonItem:_rightBarButtonItem animated:NO];
  }
  }

endif

@end

项目源码不做任何修改，问题解决；

添加Button：

UIBarButtonItem *leftBarItem = [[UIBarButtonItem alloc] initWithCustomView:btnBack];
self.navigationItem.leftBarButtonItem = leftBarItem;
[leftBarItem release];

博文地址：http://www.cnblogs.com/maxfong/p/3375167.html